SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e1fecadb2009501bca7649641a7edf46edca7395efce4c6968e4788db9f6f830' 
  AND token = 'pvOJCfMLSKV+CeJpVSr7GECInL66a3cHWEOvasrxjB4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}